[Science Codex] State renewables portfolio standards, known as RPS policies, have contributed to more than half of all renewable electricity growth in the United States since 2000. Most state RPS requirements will continue to rise through at least 2020, if not beyond, and collectively these policies will require substantial further growth in U.S. renewable electricity supplies. These findings are part of a new annual status report on state RPS policies, from Lawrence Berkeley National Laboratory (Berkeley Lab).